Manual device for examining a body fluid

ABSTRACT

The present invention provides a portable blood sugar measuring device comprising a tape unit for winding a test tape forward in sections, a detection unit for detecting measured values on the sections of tape to which body fluid has been applied, and a housing to hold the tape unit and detection unit. The tape unit and/or the detection unit can be deflected relative to the housing from an operating position against a flexible restoring element when subjected to a shock load. Also disclosed is a novel cover having open and closed positions. The cover is positioned at an opening of the housing through which the receiving site of the tape unit protrudes. The cover thus protects the receiving site from external effects when the cover is in the closed position. Similarly, the receiving site is accessible to apply body fluid thereto when the cover is in the open position.

RELATED APPLICATIONS

This is a divisional application of U.S. application Ser. No.11/405,257, filed Apr. 17, 2006, now U.S. Pat. No. 7,758,808, which is acontinuation application of International Application PCT/EP2004/011311,filed Oct. 9, 2004, which claims priority to DE 103 48 283.0, filed onOct. 17, 2003, all of which are incorporated herein by reference.

BACKGROUND

The present invention relates in general to a handheld test device foranalyzing a body fluid and in particular to a portable blood sugarmeasuring device having a tape unit for advancing a test tape insections, a detection unit for recording measured values on the testtape sections to which body fluid has been applied in the area of areceiving position, and a housing for holding the tape unit anddetection unit.

Regular blood sugar monitoring is essential for diabetics because theirtreatment, diet and rhythm of life must often be adjusted based upontheir monitored glucose levels. Handheld instruments that operate as“mini-laboratories” are widely available for self-monitoring and allowthe necessary steps to be carried out simply and rapidly, even bylaymen. Typically, disposable test strips are provided that are insertedinto the instrument for determining glucose level, for example, by anoptical measuring unit after the test strip is dosed with capillaryblood. However, the storage and processing of these test strips requirea large amount of space and also require complicated drives.

EP Applications No. 02026242.4 and 02028894.0 propose that a wound testtape on which a plurality of test sections provided with a suitable testchemistry are arranged consecutively should be used instead ofindividual test strips. The body fluid is applied and analyzed on a testsection that is moved into an active position by advancing the tape.These patent applications give details about blood collection and alsoon the known test media and detection systems, especially for bloodglucose, to which reference is herewith made and the content thereof isincorporated into this application.

In order to exactly dose the smallest possible amounts of blood, it hasbeen proposed to expose the test tape over a deflection head external tothe housing. A problem with this approach is protecting the complicatedand sensitive measuring arrangement against external influences and toexactly align the detection optics.

SUMMARY OF THE INVENTION

The present invention addresses the disadvantages noted above andprovides a robust device that that operates reliably.

In one form thereof, the present invention provides a handheld devicefor analyzing a body fluid. The device comprises a tape unit configuredto wind a test tape forward, the tape unit having a receiving siteadapted to receive body fluid. The device includes a detection unitconfigured to analyze sections of the tape to which body fluid has beenapplied. A housing is provided which holds the tape unit and thedetection unit. A flexible restoring element is disposed in the housing,and at least one of the tape unit and the detection unit are moveablerelative to the housing from an operating position against the force ofthe flexible restoring element when subjected to a shock load.

As a result of the shock absorption provided by the device of thepresent invention, the sensitive measuring arrangement is notexcessively stressed when an external force is applied, but rather canwithdraw or retract inside the housing so that the main load is absorbedby stable housing structures. Moreover, the restoring force can enablean exact centering in the operating position without the structuresconcerned having to be manufactured with extreme precision.

For particularly good protection it is advantageous that the tape unitand/or the detection unit can be deflected away from the receivingposition into the housing. In certain exemplary embodiments, thedetection unit is elastically supported against the housing by means ofthe restoring element.

With regard to the force introduction and positioning in the operatingposition, it is advantageous when the tape unit and the detection unitare held in a defined position relative to one another by means of atleast one rigid stop, in particular, opposing engagement surfaces, underthe restoring force of the restoring element.

In order to simplify the handling it is advantageous when the tape unitand the detection unit can be detached from a mutual stop position by arelease mechanism acting on the restoring element. In this connection,the release mechanism is advantageously connected to a housing cover tofurther simplify tape unit replacement.

In order to limit freedom of movement when absorbing a shock, it isadvantageous when the detection unit and/or the tape unit are mounted ina housing guide preferably with a large degree of play, i.e., play whichis not due to manufacturing tolerances. An advantageous embodimentprovides that the detection unit and/or the tape unit are guided by asliding carriage in the housing in a linearly of substantially linearlymovable manner. A further simplification results from the fact that thesliding carriage can be driven by a gear unit using an advancing drivefor the test tape.

The restoring element is advantageously elastic and in certainembodiments is spring-elastic or rubber-elastic. In this connection, incertain embodiments, the restoring element is formed by a spring and inparticular by a pressure spring pretensioned in the operating position.

In exemplary embodiments, the tape unit has a receiving head whichprotrudes from the housing in the operating position in order to exposethe test tape outside the housing. In order to initially absorb the loadfrom a shock, it is advantageous that the receiving head is formed fromspring steel that is designed to be elastically deformable.

In another form thereof, the present invention provides a handhelddevice for analyzing a body fluid, comprising a tape unit configured towind a test tape forward in sections and having a receiving site adaptedto receive body fluid. A detection unit is provided that is configuredto analyze sections of the tape to which body fluid has been applied. Ahousing is provided which holds the tape unit and the detection unit. Acover is attached to the housing, the cover having open and closedpositions, whereby the receiving site can be screened from externaleffects when the cover is in the closed position and whereby thereceiving site is accessible to apply body fluid thereto when the coveris in the open position.

Thus, the cover of the present invention enables sensitive instrumentstructures to be protected from external forces and also frompenetration by contamination. This protection is effective in theresting state when the cover is closed.

In certain embodiments, the cover advantageously includes a closingmember which can move relative to the housing and is preferably in theform of a flap, slide plate or roller blind. The cover closes an openingin the housing which bounds the receiving site.

In another exemplary embodiment, when the device is activated, the coverautomatically moves into the open position. In this connection, it isadvantageous when a tape drive that is activated when forwarding thetest tape at the same time also moves the cover device into the openposition.

In order to further improve the protective effect, it is advantageouswhen the cover can be moved into the open position when the device isoperated manually and can be automatically moved into the closedposition when the housing is released.

In order to simplify the handling and the closing function it isadvantageous when the cover has a spring mechanism which is pretensionedin the open position preferably by actuating grip elements on thehousing. It is also conceivable that a power supply inside the device isautomatically switched on by a switch or switching element when thecover is opened.

In another aspect of the invention, the tape unit is advantageouslyformed by an exchangeable cassette whereas the sections of test tape areformed by reagent fields that respond to a constituent of the body fluidand are applied in sections to a continuous carrier tape.

BRIEF DESCRIPTION OF DRAWINGS

The above-mentioned aspects of the present invention and the manner ofobtaining them will become more apparent and the invention itself willbe better understood by reference to the following description of theembodiments of the invention taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a plan view in partial cross section with portions broken awayillustrating a shock-protected blood sugar measuring device fordiabetics in accordance with an embodiment of the present invention;

FIG. 2 shows the blood sugar measuring device of FIG. 1 in alongitudinal sectional view perpendicular to FIG. 1;

FIG. 3 is a plan view illustrating another embodiment of a blood sugarmeasuring device having a closing device in an open and closed positionin accordance with the present invention;

FIG. 4 is a plan view with portions broken away illustrating a bloodsugar measuring device with an opened closing device for bloodapplication to a test tape in accordance with the present invention; and

FIG. 5 is a plan view with portions broken away illustrating the bloodsugar measuring device of FIG. 4 with a closed closing device.

Corresponding reference characters indicate corresponding partsthroughout the several views.

DETAILED DESCRIPTION

The embodiments of the present invention described below are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather, the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principals and practices of the presentinvention.

The blood sugar measuring device shown in the illustrated embodimentsincludes a housing 10 which can be held in the hand, a tape cassette 12with the test tape 14 that is inserted into the housing, a detectionunit 16 which operates optically for analysing blood applied to the testtape, and a spring-elastic restoring element 18 and/or a cover orclosing device 20 for impact protection.

As shown in FIG. 1, the restoring element 18 is formed by a compressionspring, which is pretensioned along the longitudinal axis of the devicewith its spring ends attached to a support 22 that is fixed in thehousing and an arm 24 of the detection unit 16. The restoring force ofthe compression spring 18 has the effect that the detection unit 16 andthe tape unit 12 are held in a defined stop position relative to oneanother and to the housing 10 by means of wedge-shaped stop faces 26,28.

According to FIG. 2, the tape cassette 12 can be detached from its stopposition by a release mechanism 30 in order to replace it. The releasemechanism 30 has a connecting lever 32 which is pivoted at its ends on ahousing flap 34 and on a draw hook 36. The draw hook 36 is pulled backwhen the housing flap 34 is swung open (dashed line in FIG. 2). At abouthalf the return distance, the draw hook engages the arm 24 of thedetection unit 16 and pulls it back against the force of the restoringspring such that the tape cassette 12 is released and can be removed.When the housing flap 34 is closed, a leaf spring 38 ensures that thetape cassette 12 rests on the detection unit 16 and in the housing 10 ina force-locking or secure manner.

In the stop position shown in FIGS. 1 and 2, the tape cassette 12 andthe detection unit 16 are in an operating position for acquiringmeasured data. In this position, a conical receiving head 40 of the tapecassette 12 projects from a measuring opening 42 of the housing 10 andthus enables a dosed application of blood on the receiving site 44 inthe area of its tip. The receiving head 40 forms a guide for the testtape 14 that is exposed to the outside, the test tape being wound insections in the interior of the tape cassette by means of winding spoolsthat are not shown in FIGS. 1 and 2.

The test tape 14 has a plurality of reagent fields that are appliedspaced apart on a continuous transparent carrier tape and are broughtsuccessively into use by appropriately winding the tape and reacting thereagent fields to an analyte in a drop of blood applied thereto, whichresults in a color change. This reaction is detected by a reflectionphotometric measurement by means of the optical system 46 of thedetection unit 16. In the operating position, the optics of system 46are exactly focused on the receiving site 44.

In the case of shock loading (i.e., absorbing shock), for example, whenthe device is accidently dropped, the receiving head 40, which is incontact with the sensitive detection unit 16, can withdraw or retractinside the housing against the restoring force of the compression spring18, such that the load is essentially absorbed by the stable housing 10.There is sufficient free space between the detection unit 16 and thedraw hook 36 (see FIG. 2) such that movement may take place along thepath of the spring. Moreover, when the receiving head is positioned awayfrom the stop position there is some freedom of movement relative to thehousing in all axes of freedom so that an impact that is not directedaxially can be absorbed in a favorable manner. The receiving head 40,for example, in the form of a spring steel guide, is expedientlydesigned to be elastically deformable in order to absorb initial peakforces.

Although not specially illustrated in the Figs., the detection unit 16and the tape cassette 12 can be guided on a slide carriage in thehousing to allow a linear movement. The spool drive for the test tape,which is in any case required, can be used as the drive, the rotarymovement being converted by a gear into a linear movement of the slidecarriage.

In the embodiments shown in FIGS. 3 to 5, the area of the receiving site44 is exposed when the closing device 20 is positioned in the openposition as shown in FIG. 4. Blood application, for example, from afinger tip 46 (FIG. 4), can be screened from the action of externalforces in the closed position (FIG. 5). For this purpose the closingdevice 20 has two half-shell flaps 48 which pivot around a common axisof rotation 52.

According to FIG. 3 each closing flap 48 can be actuated by means of itsown spring mechanism 50. This mechanism comprises a two-armed hand lever56, the driving arm 58 of which projects into a grip recess 60 of thehousing 10, its angled support arm 62 being supported against thehousing 10 via a spring 64 and connected to a closing flap 48 via a rod66. The closing flap 48 is held in the closed position under springtension as shown in FIG. 3 for the lower half of the housing. If thedriving arm 58 is operated manually against the force of the spring 64,the rod 66 pulls the closing flap 48 into the open position shown at thetop of FIG. 3. In this manner, it is possible for the closed position tobe automatically adopted when the device is intentionally oraccidentally released.

The embodiment shown in FIGS. 4 and 5 includes electrical grip switches60 which in the spring-loaded pressed switch position activates thedevice and thus opens the closing flaps 48 by a motor drive. For thispurpose it is possible to use a tape drive 66 which drives the windingspools 62, 64 of the tape cassette 12, which can be connected to theclosing flaps 48 by a suitable gear means. In the activated state, thedevice is held by the fingers 68 in one hand while blood is collected asdescribed above from a finger 46 of the other hand and analysed and theresult of the measurement can be read by means of the display 70. Whenthe device is put down and released the closing flaps 48 areautomatically closed over the opening 42, thus screening the receivingsite 44 from intruding contamination.

While exemplary embodiments incorporating the principles of the presentinvention have been disclosed hereinabove, the present invention is notlimited to the disclosed embodiments. Instead, this application isintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

1. A handheld device for analyzing a body fluid, comprising: a tape unitconfigured to wind a test tape forward in sections and having areceiving site adapted to receive body fluid; a detection unitconfigured to analyze sections of the tape to which body fluid has beenapplied; a housing which holds the tape unit and the detection unit, thehousing having an opening which provides access to the receiving site ofthe tape unit; a cover attached to the housing, the cover having openand closed positions and an elastic element biasing the cover in theclosed position, the cover covering the opening in the closed position,wherein the receiving site can be screened from external effects whenthe cover is in the closed position and whereby the receiving site isaccessible to apply body fluid thereto when the cover is in the openposition; and a switch in communication with the cover and configured toautomatically switch on a power supply inside the device when the coveris opened.
 2. The handheld device of claim 1, wherein the cover has atleast one closing member which can move relative to the housing.
 3. Thehandheld device of claim 1, wherein the cover is configured to close anopening in the housing which bounds the receiving site.
 4. The handhelddevice of claim 1, wherein the cover automatically moves into the openposition when the device is activated.
 5. The handheld device of claim1, further comprising a tape drive that forwards the test tape and movesthe cover into the open position.
 6. The handheld device of claim 1,wherein the cover moves into the open position when the device isoperated manually and automatically moves into the closed position whenthe housing is released by the user.
 7. The handheld device of claim 1,wherein the tape unit comprises an exchangeable cassette.
 8. Thehandheld device of claim 1, further comprising a flexible restoringelement disposed in the housing, at least one of the tape unit and thedetection unit being deflectable relative to the housing against theflexible restoring element when subjected to a shock load.
 9. Thehandheld device of claim 8, wherein the flexible restoring elementcomprises a spring connected to the detection unit.
 10. The handhelddevice of claim 8, wherein the at least one of the tape unit and thedetection is movable along multiple axes of freedom when subjected to ashock load.
 11. A handheld device for analyzing a body fluid,comprising: a tape unit configured to wind a test tape forward insections and having a receiving site adapted to receive body fluid; adetection unit configured to analyze sections of the tape to which bodyfluid has been applied; a housing which holds the tape unit and thedetection unit, the housing having an opening which provides access toand bounds the receiving site of the tape unit; a cover attached to thehousing, the cover having open and closed positions, the cover coveringthe opening in the closed position, wherein the receiving site can bescreened from external effects when the cover is in the closed positionand whereby the receiving site is accessible to apply body fluid theretowhen the cover is in the open position; and a grip element disposed onthe housing and operatively connected to the cover, the grip elementcomprising a movable member having an elastic element connected thereto,wherein actuation of the grip element opens or closes the cover.
 12. Thehandheld device of claim 11, wherein the movable member projects intothe housing.
 13. The handheld device of claim 12, wherein movement ofthe grip element against the force of the elastic element causes thecover to open.
 14. The handheld device of claim 13, wherein the elasticelement comprises a spring.
 15. The handheld device of claim 11, furthercomprising a motor operatively connected to the cover, the grip elementcomprising an electrical grip switch in communication with the motor,wherein actuation of the grip element causes the motor to open or closethe cover.
 16. The handheld device of claim 15, wherein the motor isconnected to and drives the tape unit.
 17. The handheld device of claim11, further comprising a flexible restoring element disposed in thehousing, at least one of the tape unit and the detection unit beingdeflectable relative to the housing against the flexible restoringelement when subjected to a shock load.
 18. The handheld device of claim17, wherein at least one of the tape unit and the detection is movablealong multiple axes of freedom when subjected to a shock load.